Electrode.



UNITED STATLEd HEINRICH SPECKETER, 0t GRIESHEIM, GER-lilANY, ASSIQNOR TO CHEMISCHE GRIESHEIM ELECTRON, OF FRANKFORT-ON-THE-MA1N, GERMANY,

GERMANY.

A (108F012; II

ELEGTEODE.

No. 931,518. Specification of Application filed March 21, 1907.

To all whom it may concern:

Be it known that I, HEINRIcH Srnoxn'rna, a subject of the German Empire, and a resident of Griesheim-on-thefiiain, Germany, have invented certain new and useful improvements in Electrodes, of which the following is a specification.

This invention relates to the manufacture of electrodes for elect *olytic purposes from molten magnetic oxid of iron (R2 0 or of molten, peroxid of iron (Fe O that has become magnetic.

I have found that when Fefl) is melted, oxygen escapes and Fe,(),, together with a small proportion of FeO are formed. The presence of this FeO is objectionable for two reasons,-first, it causes the electrodes to break on the setting of the melt for the reason that the protoxid does not crystallize uniformly with the magnetic oxid; second,

the product will not resist chlorin or other anodic actions during electrolysis, and is dissolved by them so that after a certain time the electrodes become ineffective. To obviate these defects and to convert the FeO, formed during the melting of the Fed), as aforesaid, into Fed) I add to the mixture, while in a molten state, a small quantity of .unmelted, finely pulverized Fe O which position.

unites With the Fe() to form Fe O so that the entire mixture will be of the same com- The proportion of pulverized iron oxid must be at least suihcient to convert the whole of the existing protoxid into magnetic iron oxid, but an excess of the Fe f) is not objectionable because it dissolves in the melt in a uniform manner and crystallizes homogeneously. The oxid of iron (Fe O added to the molten mixture being in an unmelted condition, and such addition preferably occurring when the mixture is removed from the furnace, is not heated sufiiciently to form the objectionable FeO. In lieu of iron oxid, other oxids which combine with ferrous oxidof iron (FeO) to form a compound which dissolvesin magnetic oxid (Fe OQ to form a homogeneous crystallizing melt, such, for instance, as sesquioxid of chromium (C130 which combines with Pet) [to form iron chromite (FeO.C1' O,),or sesquioxid of manganese (M11 0 which combines to form iron manganite (FeO.Mn,O,),may be used. The homogeneous crystallizing melt thusproduced is poured into molds, closed at the Letters .Patent. Patents it Serial lTo. 363,671.

bottom, which may be of the usual kind. The mass solidifies gradually from the outside so that a rigid layer is first formed on the exterior which layer gradually increases in thickness toward the center of the When such layer has reached the desired thickness, the remainder of the fluid con tents of the mold is returned. .to the melted vessel to be used for a new charge. The mold is then opened and the electrode, which is closed at its lower end, is removed and allowed to cool slowly. The cooled electrode may for the purpose of increasing its conductivity be provided on its inside with a coating of metal applied by electro deposition or otherwise, or a bar or red of good conducting metal, such, for instance, as copper, nickel, or the like, may be introduced into the central part of the mass, while it is still liquid, so that the bar or rod will form an' integral part of the electrode when the mass is completely solidified.

Electrodes prepared in the manner de scribed meet the most stringent requirements of electrolysis as they are not injuriously affected by mechanic 1 or, chemical action while in use, and possess good conductivity.

Having thus described the invention, what is claimed is: I

l. The herein described process of manufacturing electrodes for electrolytical pur poses which consists in adding to molten in a liquid state," such metal oxid as will combine with the ferrous oXidof iron (FeO) present in the molten mass and produced by the melting operatiomto form e-compound which dissolves in the molten magnetic iron 'OXlCl, producing with the latter a homogeneous crystallizinq melt, and pouring the mixture into suitab e molds.

QJThe herein described process of manufacturing electrodes for electrolytical purposes which consists in adding to moltenmagnetic iron-oXid (FeyO while it is in a liquid state such metal oxid as will combine with the ferrous oxid of iron (FeO) present in the molten mass to form a compound which dissolves in the molten magnetic iron oxid, forming with the latter a homogeneous crystallizingmelt, and pouring the mixture liquid mass.

magnetic iron-oxid (Fe OQ while it is stillinto suitable molds, allowing the mass to- 10 portion'of the mass a rod of good conduct- 3. 'lhe he'reii described process of manuing material and then permitting the mass facturing electrodes for electrolytic purto harden; poses which consists in adding to molten In testimony whereof I have signed my magnetic iron-oxid (Fe O While it is still name to this specificationin the presence of in a liquid state, such metal OXid as will two subscribing Witnesses.

result in forming a homogeneous crystallizr ing melt, and pouring the mixture into suit- HEINRICH SPEOLETER' able molds, allowing it to cool and solidify \Nitnesses: j v

superficially, inserting in the center molten FRANZ HAssLAoHnn,

ERWIN DIP'PEL. 

